require 'digest/sha1'
class Teacher < ActiveRecord::Base
  validates_presence_of     :account, :password
  validates_uniqueness_of   :account
  attr_accessor :password_confirmation
  validates_confirmation_of :password
  
  def validate
    errors.add_to_base("Missing password") if hashed_password.blank?
  end
  def self.authenticate(account, password)
    teacher = self.find_by_account(account)
    if teacher
      expected_password = encrypted_password(password, teacher.salt)
      if teacher.hashed_password != expected_password
        teacher = nil
      end
    end
    teacher
  end
  
  def password
    @password
  end
  
  def password=(pwd)
    @password = pwd
    return if pwd.blank?
    create_new_salt
    self.hashed_password = Student.encrypted_password(self.password, self.salt)
  end
  
  private  
  
  def create_new_salt
    self.salt = self.object_id.to_s + rand.to_s
  end
  
  def self.encrypted_password(password, salt)
    string_to_hash = password + "wibble" + salt
    Digest::SHA1.hexdigest(string_to_hash)
  end
  
end
